Lino acoustic panels problems

Mounted on the wall, you look straight at it, which is not comparable to the ceiling at all. The TE has also chosen a rather fine decor with a distinctive shadow gap (=contrast). No one can escape that when constantly looking at it.

The only option left is to remodel or break the pattern.

We also have it on a wall (in the living room) including a continuous shadow gap. I agree with you. Only the two options you mentioned remain.

Does the wall in the living room bother you or do you also notice a flickering like the OP? We have the same on a living room wall and now I'm unsure…

Looks great and does not disturb / flicker at all.

Does it bother you on the wall in the living room or do you, like the OP, also notice some flickering?
We have that on a living room wall as well and I'm now uncertain…

We also covered a wall with Ligno (living room, TV hangs in front of it).
I can only strongly advise following the manufacturer's instructions. The OP's decor is precisely the negative example here, as he chose relatively wide joints with rather narrow wooden slats, which were also contrasted by being darkened. Make narrower joints, don't color them, and tend to choose wider wooden slats. Then it will be fine.
We chose the 3D decor. That also breaks up the lines a bit.

I took a look at the 3d profile, I like it very much. We will think about it, it is also planned with us to have the living room wall with a hanging TV in front of it.